<!DOCTYPE html>
<style>
table {
  border-collapse: collapse;
  border: 20px solid green;
}
td {
  width: 100px;
  height: 100px;
}
</style>
Table with overflow: hidden should not clip off outer halves of collapsed borders. Passes if no red.
<table>
  <tr><td></td></tr>
</table>
